Staphylococcus aureus can cause a variety of bacterial infections ranging from common skin infections to life-threatening pneumonia or bacteremia (Pantosti et al. (2009) What is MRSA? Eur. Respir. J. 34:1190-1196). In particular, methicillin-resistant S. aureus (MRSA) poses an imminent risk to immunocompromised patients in healthcare settings all over the world. In addition, the incidence of community-acquired MRSA infections has increased among otherwise healthy individuals (Naimi et al. (2003) Comparison of community- and health care-associated methicillin-resistant Staphylococcus aureus infection. JAMA 290:2976-2984). The initial occurrence of S. aureus strains resistant to vancomycin, an antibiotic used to treat severe MRSA infections, underlines the urgent need for novel anti-staphylococcal drugs (Sievert et al. (2008) Vancomycin-resistant Staphylococcus aureus in the United States, 2002-2006. Clin. Infect. Dis. 46:668-674).